Drug – bio-affecting and body treating compositions – Topical sun or radiation screening – or tanning preparations
Reexamination Certificate
2000-02-14
2001-05-08
Dodson, Shelley A. (Department: 1616)
Drug, bio-affecting and body treating compositions
Topical sun or radiation screening, or tanning preparations
C424S401000, C424S070100
Reexamination Certificate
active
06228348
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present application relates to a composition in the form of an oil-in-water emulsion comprising at least one acrylic terpolymer and to the use of the composition, in particular for caring for and/or treating the skin of the body or of the face, the hair and/or the lips and especially for caring for dry skin and/or dry lips.
2. Discussion of the Background
For various reasons relating in particular to better comfort of use (softness, emollience and others), current cosmetic compositions are generally provided in the form of an emulsion of the oil-in-water (O/W) type composed of a continuous aqueous dispersing phase and of a non-continuous oily dispersed phase or of an emulsion of the water-in-oil (W/O) type composed of a continuous oily dispersing phase and of a non-continuous aqueous dispersed phase. O/W emulsions are the most in demand in the cosmetics field because they comprise an aqueous phase as external phase, where the aqueous phase confers, during application to the skin, a fresher, less greasy and lighter feel than W/O emulsions.
The emulsions are generally stabilized by appropriate emulsifying surfactants which, by virtue of their amphiphilic structure, become positioned at the oil/water interface and thus stabilize the dispersed droplets. These emulsifiers exhibit the disadvantage, however, of being penetrating and potentially irritating to the skin, eyes and scalp, in particular for subjects with sensitive skin.
In addition, such emulsions can have inadequate cosmetic and physicochemical properties (oily feel, instability over time). Increasing the level of surfactants does not generally solve these problems. The required stability is not always achieved and the cosmetic properties are not improved (waxy and heavy feel and lack of freshness on application). Furthermore, as indicated above, it is also inadvisable to use an excessively high level of surfactant so as to ensure harmlessness.
One solution for achieving freedom from the phenomena of instability of the O/W emulsions (creaming and phase separation) consists in adding thickening agents to the emulsion. The function of which thickening agents is to create, within the aqueous phase, a gelled matrix which serves to set the oily droplets and which provides for mechanical maintenance of the entire emulsion. However, this solution exhibits the disadvantage of not making it possible to obtain all the desired textures and in particular fluid and light textures which are readily and rapidly applied to the skin without leaving a residual film.
Furthermore, the replacement of the surfactants by polymers comprising, in their chains, a hydrophilic part and a hydrophobic part composed of a fatty chain, such as copolymers of (C
10
-C
30
)alkyl acrylate and of acrylic or methacrylic acid, for example the product “Pemulen TR2” sold by Goodrich, has been envisaged. However, these polymers exhibit the disadvantage of not making it possible to obtain a composition which remains stable for a long period of time when the amount of oil is too high or when the emulsion is very fluid, that is to say in the case where the aim is to minimize the level of polymer in order not to have a thick emulsion.
SUMMARY OF THE INVENTION
An object of the present invention is to provide stable oil-in-water emulsions which optionally do not comprise an emulsifying surfactant conventionally used in O/W emulsions and which exhibit good cosmetic properties without having the disadvantages of the prior art and whatever the amount of oil present in the emulsion.
The Inventors have discovered, unexpectedly, a novel family of polymers allowing the preparation of oil-in-water emulsions which are stable although optionally devoid of conventionally used surfactant.
Thus, the present invention provides a composition in the form of an oil-in-water emulsion comprising, in a physiologically acceptable medium, an oily phase dispersed in an aqueous phase, which comprises at least one acrylic terpolymer obtained from the polymerization of
(a) an &agr;,&bgr;-ethylenically unsaturated carboxylic acid monomer;
(b) a non-surface-active ethylenically unsaturated monomer other than (a); and
(c) a non-ionic urethane monomer, which is the reaction product of a monohydric non-ionic amphiphilic compound with an monoethylenically unsaturated isocyanate,
wherein the weight ratio of the terpolymer to the oily phase is from 1150 to 1/125.
The present invention also relates to a method of treating, protecting, caring for, removing make-up from and/or cleansing the skin, lips and/or hair and/or for making-up the skin and/or lips, comprising applying the inventive composition to the skin, lips and/or hair.
The present invention also relates to a method of cosmetically treating the skin, hair and/or lips, comprising applying the inventive composition to the skin, hair and/or lips.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description.
BRIEF DESCRIPTION OF THE INVENTION
The composition of the present invention has a homogeneous texture which is pleasant on application. In addition, the acrylic terpolymer used in the composition according to the invention makes it possible to prepare oil-in-water emulsions which remain stable over time at room temperature or at higher temperatures and to retain these properties of the emulsion whatever the fluidity of the emulsion and its content of oily phase. It is thus possible to prepare both thick emulsions having a high content of oily phase, which are particularly effective in the treatment of dry skin, and very fluid emulsions.
The viscosity of the emulsions can therefore vary to a large extent and can range in particular from 0.05 Pa•s to 8 Pa•s, these viscosities being measured at approximately 25° C. using a “Rheomat 180” viscometer which is generally equipped with a 2 rotor for viscosity ranges from 0.02 Pa•s to 0.7 Pa•s, with a 3 rotor for viscosity ranges from 0.2 Pa•s to 4 Pa•s, and with a 4 rotor for viscosity ranges from 2 Pa•s to 23 Pa•s. These ranges for the viscosity include all specific values and subranges therebetween, such as 0.05, 0.1, 0.5, 1, 5, 10, 12, 15 and 20 Pa•s.
The emulsion of the invention is preferably devoid of surfactant conventionally used in O/W emulsions and it exhibits, for this reason, the advantage of not being irritating to particularly sensitive skin. In addition, this emulsion exhibits the advantage of making possible the incorporation of heat-sensitive active principles as it can be manufactured at room temperature, both in the stage of neutralization of the polymer and in the stage of dispersion of the oily phase.
The acrylic terpolymer used in accordance with the invention is soluble or swellable in alkaline substances. It is preferably characterized in that it comprises, with respect to the total weight of the terpolymer:
(a) Approximately 20 to 70% by weight, preferably 25 to 55% by weight, of an &agr;,&bgr;-monoethylenically unsaturated carboxylic acid monomer. These ranges include all specific values and subranges therebetween, such as 30, 35, 40, 45, 50, 60 and 65% by weight,
(b) Approximately 20 to 80% by weight, preferably 30 to 65% by weight, of a non-surface-active monoethylenically unsaturated monomer other than (a). These ranges for the viscosity include all specific values and subranges therebetween, such as 25, 35, 40, 50, 55, 60, 70 and 75% by weight, and
(c) Approximately 0.5 to 60% by weight, preferably 10 to 50% by weight, of a non-ionic urethane monomer which is the reaction product of a monohydric non-ionic amphiphilic compound with a monoethylenically unsaturated isocyanate. These ranges for the viscosity include all specific values and subranges therebetween, such as 1, 2, 5, 15, 20, 25, 30, 35, 40, 45 and 55% by weight.
The carboxylic acid comprising &agr;,&bgr;-monoethylenic unsaturation (a) can be chosen from numerous acids and
Bordeaux Dominique
Simon Pascal
Dodson Shelley A.
George Konata M.
L'Oreal
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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